Plastic corrugated and flexible tubing and especially inexpensive medical tubing which can be used as part of or in conjunction with disposable respiratory therapy devices such as oxygen masks, volume ventilator circuits, nebulizers, and the like have been of recent interest. Especially advantageous is corrugated tubing which is quite flexible and yet in lightweight and strong and incorporates a smooth interior surface as opposed to a corrugated interior. Such a tubing is described in my co-pending application Ser. No. 595,115, filed July 11, 1975.
Apparatus for producing types of flexible corrugated plastic tubing have been disclosed in U.S. Pat. Nos. 3,301,734 and 3,706,624. Both of these patented apparatus utilize a system in which a continuous strip or ribbon of molten thermosplastic is wrapped spirally on a mandrel to form the corrugated tubing. The apparatus of the present invention is an improvement and designed to produce a tubing such as described in my aforesaid co-pending application. Specific details and advantages of such an apparatus will be evident from the following detailed description.